(a) Field
The subject matter disclosed generally relates to mining equipment and, more particularly, to exploration drilling equipment.
(b) Related Prior Art
In exploration drilling, the average length of a drill hole obtained from the use of a rod string may typically be about 900 m. The rod string is typically composed of a plurality of drilling rods, which, depending on configuration, typically weigh about 11-20 kg each and measure about 2-3 m in length. The drilling rods are typically interconnected by a threaded connection.
Moreover, in many applications, also depending on rock type, tool type and drilling speed, it is a common necessity to exchange the drilling bit or other tool parts many times during the drilling process, for instance an average once every 300 m of drilling. Changing tools may be associated with retrieving the entire rod string from the hole, changing the lowermost portion of the rod string and then reinserting the entire rod string, after which drilling may continue. In practice, and depending on rock conditions, 10 to 20 retrieval operations per drill hole is not uncommon.
Needless to say, a very large number of drilling rods will need to be handled, including picking them from a transport carrier, inserting them into the drill, aligning them with the rod string, joining them to the rod string, fastening them, releasing them and replacing them at the transport carrier.
In reality, this may mean that an operator has to carry/lift an 11 to 20 kg drilling rod about 1200 times to or from the rig for each hole. With an estimated average number of holes drilled per rig of 35 holes/year, this adds up to carrying 2100 to 3820 kg of drilling rods per day for an operator (based on 220 working days per year).
Furthermore, with that number of manipulated drilling rods, there are substantial financial advantages in any solution that facilitates the alignment of drilling rods with the rod string.
There is therefore a need for improvement in devices and methods involved in carrying drilling rods and aligning them with a rod string.